4874f544f1
The default of 16m causes serious thrashing for large delta chains
combined with large files.
Here are some benchmarks (pu variant of git blame):
time git blame -C src/xdisp.c >/dev/null
for a repository of Emacs repacked with git gc --aggressive (v1.9,
resulting in a window size of 250) located on an SSD drive. The file in
question has about 30000 lines, 1Mb of size, and a history with about
2500 commits.
16m (previous default):
real 3m33.936s
user 2m15.396s
sys 1m17.352s
32m:
real 3m1.319s
user 2m8.660s
sys 0m51.904s
64m:
real 2m20.636s
user 1m55.780s
sys 0m23.964s
96m:
real 2m5.668s
user 1m50.784s
sys 0m14.288s
128m:
real 2m4.337s
user 1m50.764s
sys 0m12.832s
192m:
real 2m3.567s
user 1m49.508s
sys 0m13.312s
Signed-off-by: David Kastrup <dak@gnu.org>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
////////////////////////////////////////////////////////////////
Git - the stupid content tracker
////////////////////////////////////////////////////////////////
"git" can mean anything, depending on your mood.
- random three-letter combination that is pronounceable, and not
actually used by any common UNIX command. The fact that it is a
mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the
dictionary of slang.
- "global information tracker": you're in a good mood, and it actually
works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks
Git is a fast, scalable, distributed revision control system with an
unusually rich command set that provides both high-level operations
and full access to internals.
Git is an Open Source project covered by the GNU General Public
License version 2 (some parts of it are under different licenses,
compatible with the GPLv2). It was originally written by Linus
Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
See Documentation/gittutorial.txt to get started, then see
Documentation/everyday.txt for a useful minimum set of commands, and
Documentation/git-commandname.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with "man gittutorial" or "git help tutorial", and the
documentation of each command with "man git-commandname" or "git help
commandname".
CVS users may also want to read Documentation/gitcvs-migration.txt
("man gitcvs-migration" or "git help cvs-migration" if git is
installed).
Many Git online resources are accessible from http://git-scm.com/
including full documentation and Git related tools.
The user discussion and development of Git take place on the Git
mailing list -- everyone is welcome to post bug reports, feature
requests, comments and patches to git@vger.kernel.org (read
Documentation/SubmittingPatches for instructions on patch submission).
To subscribe to the list, send an email with just "subscribe git" in
the body to majordomo@vger.kernel.org. The mailing list archives are
available at http://news.gmane.org/gmane.comp.version-control.git/,
http://marc.info/?l=git and other archival sites.
The maintainer frequently sends the "What's cooking" reports that
list the current status of various development topics to the mailing
list. The discussion following them give a good reference for
project status, development direction and remaining tasks.